Osaka Battera, Box-Pressed Mackerel Sushi with Kombu

What you need

• 4 sheets shiraita kombu, thin shaved kombu, about 4 x 12 cm (1 1/2 x 5 in)
• 440 ml (1 3/4 cups) rice vinegar, divided: 110 ml for the kombu, 270 ml for the fish, 4 tbsp for the rice
• 90 g (7 tbsp) granulated sugar, divided: 24 g for the kombu, 40 g for the fish, 2 tbsp for the rice
• 2 very fresh mackerel fillets, skin on, from 1 large mackerel, previously frozen if possible
• 1 tbsp salt, plus 1 tsp for the rice
• 300 g (1 1/2 cups) Japanese short-grain rice
• 360 ml (1 1/2 cups) water
• 1 piece kombu, about 3 x 3 cm (1 x 1 in), for cooking the rice
• pickled ginger, for serving

Method

Restated from the original video

1. 1

   The day before, stir 110 ml of the vinegar with 24 g of the sugar until dissolved, lay the kombu sheets in it and leave overnight.

2. 2

   Lay the mackerel skin side down and run a finger along the middle to find the line of pin bones. Cut a shallow strip out on either side of it and discard the bones.

3. 3

   Cover the mackerel on both sides with the 1 tbsp salt and leave for 30 min, until it firms up and gives off liquid.

4. 4

   Rinse off the salt and pat the fillets dry. Mix 270 ml of the vinegar with 40 g of the sugar, lay the fish in it and leave for 1 hour.

5. 5

   Meanwhile, wash the rice in several changes of water until it runs clear, soak it for 20 min and drain well.

6. 6

   Put the rice, water and small square of kombu in a heavy pan with a lid. Cook covered over high heat for 5 min, then on low heat for 20 min until the water is absorbed. Rest 10 min off the heat.

7. 7

   Warm the remaining 4 tbsp vinegar with the remaining 2 tbsp sugar and 1 tsp salt until dissolved.

8. 8

   Tip the hot rice into a wide bowl, discard the small square of kombu and sprinkle over the seasoned vinegar. Fold it in with cutting strokes of a paddle while fanning, until the rice is glossy and at body temperature. Cover with a damp cloth.

9. 9

   Lift the mackerel from its marinade and pat dry. Peel off the thin, clear outer skin from head end to tail, leaving the silver pattern underneath.

10. 10

    Slice the thick part of each fillet horizontally so it lies flat and even, keeping the trimmings to fill gaps.

11. 11

    Wet a sushi press or a small rectangular box lined with plastic wrap with water and a little vinegar. Lay one fillet in it skin side down, patching gaps with trimmings.

12. 12

    Pack in half the rice, pressing it into the corners, then put on the lid and press down firmly with your full weight.

13. 13

    Turn the pressed block out with the fish on top and lay two kombu sheets over it. Repeat with the second fillet and remaining rice.

14. 14

    Wrap each block tightly in plastic wrap and rest in the fridge for 10-30 min so it holds together.

15. 15

    Cut through the wrap into 6 pieces per block with a sharp, wet knife, wiping it after each cut. Unwrap and serve with pickled ginger.

16. 16

    This dish uses cured, uncooked fish: buy mackerel sold for raw eating, or freeze it first, and serve it the day it is made.

Imported from justonecookbook.com. Recipe Grab pulled out what you need to cook it; the video stays where its author put it.